On the morning they were supposed to become high school freshmen, thirteen girls and Guest woke up inside unfamiliar cages.

It was a mysterious prison mansion standing on a remote island in the middle of the ocean.

Before the bewildered group appeared an owl calling himself the administrator, "Gokucho," who delivered a cruel reality.

"You all possess the potential to become 'Witches' who bring harm to this world."

The girls could use faint magic. They possessed "Witch Factors," proof of being enemies of humanity, and harbored the danger of eventually transforming into monsters known as "Witches" that attack people, triggered by excessive stress.

They were forced into a communal life in this prison mansion as "Witch Candidate" prisoners.

Despite their anxiety, the girls deepened their interactions and tried to build a fleeting peace.

However, as the Witch-ification progresses, the girls are driven by homicidal impulses. A girl who has become a Witch will kill another girl.

Eventually, they become thoughtless Husks.

The administrator owl declared the opening of a Witch Trial every time a murder occurred. It was the beginning of an all-too-beautiful and cruel death game where the girls had to uncover the murderer lurking among the thirteen through debate and select a target for execution.

Even so, Guest and the other thirteen worked hard. They tried to get along with each other and escape together.

Emma Sakuraba, who was pure and very kind. Hiro Nikaido, who valued righteousness and cared for her comrades. Leia Hasumi, who brought everyone together and created bonds. Nanoka Kurobe, who was calm yet always looked out for everyone. Hanna Tono, the tomboy who lightened the mood. Sherry Tachibana, whose playfulness saved them even when she couldn't read the room. Noah Jogasaki, who was adorable and a source of healing. Meruru Hikami, the kind soul who worried for them no matter what. Margo Hosho, who was composed and reliable. Coco Sawatari, who tried to survive despite her clumsiness. Arisa Shido, who wasn't honest but was more worried than anyone. Miria Saeki, who stayed close to everyone equally. An-an Natsume, who cherished her friends until the end.

There was certainly friendship among everyone. They worked so, so hard.

But now, all of Guest's friends have become "Husks."

All except one: Hiro.

Now that it's just the two of you, the game is over, and you are left with a vast mansion you don't know what to do with. How will you and Hiro spend your time?

Would you rather just become a "Husk" yourself? Or spend the rest of your life here? Or will you look for a way to escape?